2 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. I23 



R. B. Eads, Texas State Board of Health ; V. J. Tipton, Army Medi- 

 cal Service Graduate School ; and G. H. E. Hopkins and F. G. A. M, 

 Smit, British Museum. 



To a great extent this paper is based upon material in the U. S. 

 National Museum, to which we were allowed access. That museum 

 is serving as depository for the types of the new form described herein 

 and for specimens of the previously unknown female of Peromysco- 

 psylla draco. 



We are also deeply indebted to Dr. Karl Jordan, F.R.S., for his 

 generous help in the early stages of this study, and to G. H. E. Hop- 

 kins and the Honorable Miriam Rothschild for allowing us to quote 

 synonymy from their excellent manuscript on fleas in the N. C. Roths- 

 child Collection. 



Thomas Evans, Department of Entomology, Army Medical Service 

 Graduate School, kindly drew copies of Skalon's Peromyscopsylla 

 ostsibirica figures for inclusion in this paper. 



Genus PEROMYSCOPSYLLA I. Fox, 1939 



Peromyscopsylla I. Fox, Proc. Ent. Soc. Washington, vol. 41, p. 47, 1939; Fleas 

 of the eastern United States, pp. 8, 78, 84, 1940. — Jellison and Good, U. S. 

 Public Health Service, Nat. Inst. Health Bull. 178, p. 121, 1942. — Ewing 

 and Fox, U. S. Dept. Agr. Misc. Publ. No. 500, p. 90, 1943. — Hubbard, 

 Fleas of western North America, pp. 274, 328, 1947. — Holland, Canada 

 Dept. Agr. Techn. Bull. No. 70, pp. 54, 175, 1949. — Hopkins, Ann. Mag. 

 Nat. Hist., ser. 12, vol. 4, pp. 540, 541, 1951. 



Head. — Fracticipate. Bullet-shaped, preantennal region with 

 strongly rounded anterior and dorsal margins, more than twice as 

 high as broad at level of distinct but reduced frontal tubercle. Anterior 

 margin with a row of bristles of which two to four are usually spini- 

 forni. Preantennal region with five or six nonmarginal bristles and 

 two or three shorter ones near dorsal margin. Eye reduced. Anterior 

 tentorial arm (fig. i, A.T.A.) visible anterior to eye. Labial palpus 

 5-segmented, about one-half length of forecoxa. Genal ctenidium of 

 two distinct horizontal, posteriorly directed spines, one above the 

 other; heavily pigmented genal process (fig. i, G.P.) above genal 

 spines, but at times hidden by more dorsal spine. With a genal lobe 

 (figs. I, 74, G.L.) of varying length ventral to spines of ctenidium. 

 Postantennal area with three to five rows of bristles ; with one rather 

 stout bristle near posteroventral angle of antennal groove. No tuber 

 present on upper margin of antennal groove. 



Thorax. — Procoxa articulated at anterodorsal angle of prosternum. 

 Pronotal ctenidium of 24 to 30 long dark spines. Lateral metanotal 

 area about i^ times as long as high. Pleural arch well defined. 



